The search for new antimicrobials is a critical process as many species of bacteria are becoming resistant to multiple antibiotics.
Currently, the most active approach to finding new antimicrobials is the chemical modification of existing antibiotics, many of which are produced by bacteria or fungi. A significant drawback to this approach is that natural antibiotics and resistance to natural antibiotics coevolved, in part to protect the producing organisms.
Some peptide antimicrobials have been identified using standard antimicrobial screening technologies or by generating peptide libraries and screening for peptides that bind to a specific target. Examples of peptide screening technologies are phage display and ribosome display.
While these techniques can be effective at identifying antimicrobial peptides, there are drawbacks associated with their use. For example, the methods often use in vitro screening methods to identify antimicrobials that bind to known targets. This strategy does not identify antimicrobials that are effective based on interaction with an unknown or unchosen target. Moreover, in vitro screening assumes that a target's structure and its interaction with the peptide will be the same in vitro as in vivo. In many cases, however, there are significant differences between in vitro and in vivo conditions. Accordingly, there is room for improvement in techniques and methods used to identify new antimicrobial compounds.